In general, a high speed rail road such as Shinkansen adopts an alternate current electrification system to ensure high power. In the alternate current electrification system, since power is supplied from individual substations, a section is provided to isolate a neighbor power source. Such a configuration is specifically illustrated in FIG. 9.
As illustrated in FIG. 9, in the alternate current electrification system, an internal section 100 is disposed between two power supplies G1 and G2 in order to isolate the power supplies G1 and G2 from each other. The length of the internal section 100 is typically set to about 1 km.
When a train 101 passes through the internal section 100 from the left to the right of a sheet, a section switch VS1 is first closed to charge the internal section 100. Subsequently, while the train 101 passes through the internal section 100, the section switch VS1 is opened, and the section switch VS2 is closed so that a charge source of the internal section 100 is changed from G1 to G2. Dead time during this operation is controlled to about 0.05 to 0.3 sec, so that the train 101 can pass through the internal section 100 while maintaining its high speed condition. When the train 101 has passed through the internal section 100, the section switch VS2 is opened.
Examples of a switchgear applicable to the section switches VS1 and VS2 include a double break switch described in PTL 1 (Japanese Unexamined Patent Application Publication No. 2007-188734). In the double break switch described in PTL 1, two series switches are opened or closed substantially simultaneously.